A warp field specialist is an engineer who specializes in warp fields.
Henry Archer was a famed warp specialist who created the warp five engine. (ENT: "In a Mirror, Darkly, Part II")
A warp field specialist can be responsible to writing specifications for starship operations, as was the case for the dilithium matrix for the Template:ShipClass. Although the specs stated that the matrix had to be aligned to 0.5 microns, Charles Tucker felt that they should be within 0.3 microns. When questioned by Rivers regarding his viewpoint, Tucker stated, "Who do you think wrote those specs... some guy who's probably never been outside the solar system. I've spent the last three and a half years crawling inside one of these engines. I know what I'm talking about." (ENT: "Affliction")
Sergey Rozhenko was the warp field specialist aboard the USS Intrepid. (TNG: "Family")
Kurak was a warp field specialist from Qo'noS. Beverly Crusher worked with her briefly while promoting Doctor Reyga's metaphasic shield. According to Crusher, "I don't think Klingons regard scientists highly. She always seemed a little defensive." (TNG: "Suspicions")